JSI Tip 2113. How do I restrict dial-in permissions in a Windows 2000 mixed-mode domain?

The Windows 2000 help files says to implement a policy that defines the Restrict access to the following days and times dial-in constraint, setting it to No days and No times.

This doesn't work.

Use the Restrict Dial-in to this number only constraint, and use a non-existent phone number.